From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [net PATCH v2] gro: Allow tunnel stacking in the case of FOU/GUE Date: Tue, 29 Mar 2016 14:55:22 -0700 Message-ID: <20160329215226.12478.3696.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: jesse@kernel.org, netdev@vger.kernel.org, davem@davemloft.net, alexander.duyck@gmail.com, tom@herbertland.com Return-path: Received: from mail-pa0-f54.google.com ([209.85.220.54]:33199 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754171AbcC2VzY (ORCPT ); Tue, 29 Mar 2016 17:55:24 -0400 Received: by mail-pa0-f54.google.com with SMTP id zm5so23963691pac.0 for ; Tue, 29 Mar 2016 14:55:24 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: This patch should fix the issues seen with a recent fix to prevent tunnel-in-tunnel frames from being generated with GRO. The fix itself is correct for now as long as we do not add any devices that support NETIF_F_GSO_GRE_CSUM. When such a device is added it could have the potential to mess things up due to the fact that the outer transport header points to the outer UDP header and not the GRE header as would be expected. Fixes: fac8e0f579695 ("tunnels: Don't apply GRO to multiple layers of encapsulation.") Signed-off-by: Alexander Duyck --- v2: Dropped switch statements per suggestion of Tom Herbert. net/ipv4/fou.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index a0586b4a197d..5a94aea280d3 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -195,6 +195,14 @@ static struct sk_buff **fou_gro_receive(struct sk_buff **head, u8 proto = NAPI_GRO_CB(skb)->proto; const struct net_offload **offloads; + /* We can clear the encap_mark for FOU as we are essentially doing + * one of two possible things. We are either adding an L4 tunnel + * header to the outer L3 tunnel header, or we are are simply + * treating the GRE tunnel header as though it is a UDP protocol + * specific header such as VXLAN or GENEVE. + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); @@ -352,6 +360,14 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head, } } + /* We can clear the encap_mark for GUE as we are essentially doing + * one of two possible things. We are either adding an L4 tunnel + * header to the outer L3 tunnel header, or we are are simply + * treating the GRE tunnel header as though it is a UDP protocol + * specific header such as VXLAN or GENEVE. + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[guehdr->proto_ctype]);